Reviews—F. P. Mennell’s Miner’s Guide. 3873 
refers to Sir W. Tilden’s primer of Chemistry for an explanation of 
chemical processes. Commencing with a short account of the early 
history of the earth, he passes on to the study of rocks, dividing them 
into Primary and Secondary, the former including all the Igneous 
rocks and the latter all the Aqueous or Stratified rocks. This is not 
in accordance with the general usage of the terms, and is to be 
deprecated ; but the descriptions of the rocks and of their method of 
formation are clear and instructive. More generally interesting is 
the section on Physical Geology, in which modern agents and the 
arrangement of rocks in the field are dealt with. Here we note that 
the author applies the term erosion to the widening of a valley, and 
corrosion to the cutting of a gorge. The term erosion is by most 
geologists employed for all kinds of denudation. Under Historical 
Geology the author gives a brief account of fossils and of the geological 
systems, and introduces a short notice of Gondwanaland, which is 
illustrated by a map of the world in the Upper Carboniferous era. 
The primer should prove useful to general readers as well as to 
students and science-teachers, and is well calculated to stimulate 
further inquiry. 
V.—Tue Miver’s Guipzr. By F. P. Mennett, F.G.S. London: 
Gerrards, 1909. 4s. net. 
RESENT-DAY civilization imposes a heavy toll on the mineral 
resources of the globe. There is no metal that is not turned to 
some use. There is no quarter of the globe, not excepting the Polar 
regions, to which the discovery of mineral wealth does not instantly 
attract public attention, and there is no nation in the possession of 
more real and prospective mineral wealth than that which hes within 
our own empire. Yet how few are able to distinguish one mineral 
from another, or have any idea as to the rocks in which mineral 
deposits are likely to occur! Elaborate treatises, and textbooks beyond 
count, are on the market ; but most of these are written for the initiated 
and are not serviceable to the untrained, by whom the want of a clearly 
written and practical guide has long been felt. 
In The Miner's Guide Mr. Mennell has, we think, successfully 
supplied this deficiency in our scientific literature. How rocks and 
minerals are formed, how they occur, by what means they can be 
distinguished, and how their value may be ascertained, are made clear 
to all who possess an elementary knowledge of chemistry. Quite 
fittingly, the author illustrates his text with examples taken from his 
wide knowledge of the mineral deposits of South Africa, Rhodesia in 
particular. Other countries are referred to, but all too briefly. Coal 
and oil are summarily dismissed, and we are erroneously informed that 
the ‘‘ well-known coalfields’’ of Ireland are of Silurian age. 
The practical nature of Mr. Mennell’s clever outline is its chief 
attraction, but we think that a book dealing with a subject of such 
general interest possesses an educational value, especially as in this 
instance the information is obtained at first hand, and the writer has 
the ability to present his subject in a clear and concise manner.. 
